note: this blog post was first published on my B-eye-network blog.
It is only by means of good and respectfull discussion that knowledge and insight will evolve. This post should be regarded as such. Furthermore, it is from a good friend from whom I understood that Rick meant to be controversial with these papers.....
This post is a first reaction to the first article in a series of three which were written by a highly respectfull thoughtleader in the field and publisher on the B-Eye-Network; Rick van der Lans. The papers are titled 'The Flaws of the Classic Data Warehouse Architecture'.
This blog post is a reaction to the first part. It deals with the flaws of the classic data warehouse architecture (CDWA) according to Rick. If you wanna know what exactly constitutes a CDWA - I would suggest to read this first part.
Rick signals five flaws which will lead in article two and three to a new architecture. This post is addressing the first flaw. In upcoming postings on this blog I will also adress the other four and I will also respond to the solution he is proposing.
Flaw 1 according to Rick
The
CDWA does not support the concept of Operational Business Intelligence.
This conclusion is drawn from the fact that the CDWA can not include
100% up-to-date information. Rick concludes that we have to remove
storage layers and minimize the copy steps.
My reaction to flaw 1
A
metaphor; I am driving my car and suddenly I say 'damn; I wanna fly'.
Looking at my car, I can not seem to find the 'fly' button and I
therefore conclude that my car is flawed.
Although a bit of a
corny metaphor it reflects the core of my criticism. Aparently there is
a new requirement called Operational Business Intelligence* that can
not be served by the existing architecture. Is the existing
architecture then flawed? I do not think so. Does the existing
architecture fit the needs of the organisation? I do not think so. So
flaw 1 in my opinion is not a flaw, it might simply be not a good fit
between requirement and architecture.
Let's take this corny
metaphor one step further. Suppose there is a genuine need for me to
fly (e.g 100% up-to-date information for decision-like processes*). Is
it then considered common sense to build wings on my car and put in a
jet engine? I wouldn't ......I would just buy a plane ticket and get to
an airfield or maybe I would use a substitute to achieve my
objectives....the train.
To conclude; requirements are
evolving and architecture needs to follow. The data warehouse
architecture depicted as a hub-spoke model is still valid for it's
intented use (although the design is evolving). New requirements can lead to new choices in architecture (and subsequently in design).
Although I do not agree on the flaw issue, I do agree that new requirements can require new architecture which - in the end - is exactly what Rick is proposing (although I do not agree completely on this new architecture - but lets keep that in mind for a next posting).
*
as you can see I am eluding the tedious discussion regarding the term
Operational Business Intelligence. I am also eluding the so-called
'fact' that organizations all need 100% up-to-date information for
decision like processes.
Personally I think Rick van der Lans is overreacting to a real problem, which is a sort of reflex to pull all the data we can find into the data warehouse like gophers gathering nuts for the winter.
One example of that would be the abomination proposed in 2007 called 'the historical staging area' - in DB/M. There are other examples.
And operational business intelligence may look like a 'wtf?' thingy for nerds, but I know some people that would love to have it. Just think about Walmart and the response time they have between seeing a shift in consumer behaviour and delivering new supplies - they need all the lead time they can get.
In general I agree that Rick is generalizing a bit too much. However, some people need a wake-up call and that's what he's doing quite well.
Posted by: Ronald Kunenborg | June 21, 2009 at 03:00 PM